The present invention relates to devices for preparing coke oven doors, and particularly to descaling machines for removing deposits from the oven door refractory and milling machines for machining the oven door seal. More particularly, the invention relates to descaling machines and milling machines that are coupled to a frame which securely supports the coke oven door for maintenance purposes.
Ovens used in the production of coke generally comprise four walls which together define a long narrow internal channel therebetween. The ends of the channel are closed by removable oven doors. Typically, a coke production facility has an apparatus for removing the doors from the oven at the end of a production cycle to facilitate the removal of coke from the oven. The apparatus is generally capable of replacing the door on the oven or transferring the door to a support frame in a maintenance area.
A coke oven door generally has a door frame and a center portion of refractory material attached to the door frame which juts into the coke oven when the door is installed on the oven. A sealing strip extends around the perimeter of the door frame and presents a knife edge to a face of the door jamb. A good seal improves the efficiency of the coke oven by reducing the escape of heat past the door and reduces the hazards associated with such heat loss.
It is well known that, in order to be effective, the seal between the coke oven door and the door jamb must be gas tight. If the knife edge exactly mates with the door jamb, the knife edge will provide a gas tight seal around the door.
During the coking operation, a large amount of tar, coke, or the like deposit on the center portion and seal of the door. Cleaning the deposits from the coke oven door and seal improves the thermal efficiency of the oven and helps to ensure that the door will seat properly to provide a good seal when the door is replaced on the oven. Thus, it is necessary to clean the deposits from the door refractory and door seal at regular intervals. Ideally, the coke oven door is cleaned at the end of each cycle, when the coke oven door is removed and the coke is removed from the oven.
If any gaps exist between the knife edge and the door jamb, the tar, coke or the like will also deposit on the knife edge at the gaps, and the knife edge will also need cleaning. However, with regard to gaps between the knife and the door jamb, cleaning is not enough. In addition to fostering the formation of deposits on the knife edge, gaps between the knife edge and the door jamb accelerate wear and warpage of the knife edge by the passage of hot gases escaping from the oven at the gaps. Thus, gaps can tend to grow over time and get worse. Therefore, it is advantageous to resurface the door seal at regular intervals to ensure that the knife edge is true and thereby reduce the effect of wear and warpage of the knife edge due to heat escaping from the coke oven.
Typically, when the coke oven doer is removed from the oven for maintenance, it is moved to a maintenance area where it is mounted in a maintenance frame for cooling and subsequent cleaning and resurfacing. In the past, while the door was in the maintenance frame, the deposits were removed from the door by hand-held wire brushes. While in the maintenance frame, the door seal was also resurfaced manually by running a belt type sander over the door seal and visually inspecting the resurfaced sealing edge for trueness. The manual method of cleaning the deposits from the door has been adequate, but inefficient. Moreover, a visual inspection for trueness can prove to be inaccurate, causing problems with an improper fit when the oven door is replaced on the oven, leaving a gap between the knife edge and the door jamb. A device that would allow rapid removal of deposits from the door and seal and rapidly and accurately resurface the sealing edge of the door seal would be a substantial improvement over conventional door preparation mechanisms.
According to the present invention, a device for preparing a coke oven door includes a frame for securing the door in a working position. A milling machine for machining the door seal includes a gantry coupled to the frame and a milling head coupled to the gantry. The milling head is movable up and down, longitudinally, and transversely relative to the door so as to maintain contact with the door seal.
According to one aspect of the invention, a rail is attached to the frame and a rail extension is attached to the gantry. The rail and rail extension cooperate to guide the gantry longitudinally along the door. A rack is attached to the frame and a driven pinion is attached to the milling machine which engages the rack to move the milling machine along the rail and rail extension.
A descaling machine is movable longitudinally along the door and includes a plurality of brushes for removing deposits from the refractory and door frame. A U-shaped channel is attached to the frame for guiding the descaling machine along the door. The descaling machine includes a plurality of driven wheels for movement along the U-shaped channel.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.